The number of serious assaults on prison officers by offenders has risen significantly under the coalition prompting concerns the Government is ignoring a crisis in jails.

A total of 543 assaults by prisoners on officers in jails were referred to the police in 2012, a 45% rise from the 374 assaults referred to police in 2010 when the coalition came to power, official figures showed.

The figure equated to nearly three assaults every two days in 2012.

Shadow justice secretary Sadiq Khan said that dedicated and hard-working prison officers should not have to face violence at work and blamed the Government for allowing jails to become overcrowded.

Mr Khan, who unveiled the figures using a written parliamentary question, said: "How can ministers expect to rehabilitate criminals if prisons are dens of violence?

"On their watch, this Government have presided over prisons becoming more and more overcrowded and violent.

"We've seen call outs by the prison riot squad up sharply, and last year saw the highest number of deaths in custody for over a decade.

"And all the time prisoners are spending too much time idling away in their cells or on landings instead of undertaking meaningful activity like work, education or training.

"It's not an overstatement to say that prisons are in crisis and the Government are either oblivious or simply don't care."

Prisons Minister Jeremy Wright said the National Offender Management Service (NOMS) is reviewing policy for managing violence in prisons.

Replying to Mr Khan's question, he said: "NOMS takes the issue of assaults on prison staff very seriously. It currently has systems in place to deal with perpetrators quickly and robustly, with serious incidents referred to the police for prosecution.

"It is working with the police and Crown Prosecution Service to ensure that prisoners who assault staff are charged and punished appropriately.

"NOMS is committed to exploring options to continue to improve how violence is tackled in prisons to keep both staff and prisoners safe. It is currently reviewing the policy and practice of the management of violence."